If global warming is caused by the Sun, then why is the upper atmosphere cooling?

The sun accounts for 0.2 degrees Celsius of the warming here on Earth. Nothing more. a href="http://www.sciencedaily.com/releases/2007/08/070801174450.htm" rel="nofollow"http://www.sciencedaily.com/releases/200…/a So I would say it's a safe bet that the rest of our temperature rise must be due to heat retention.. and what retains heat? (say it with me now!) Green House Gases! woohoo!! and the home team wins again!